Control device

ABSTRACT

In a master device (control device) that employs a configuration list, setup change is performed easily without requiring a complicated operation with respect to a partial change in the configuration of a slave-side system on a slave side. A control unit (11) of a control device (10) is configured to perform communication for inquiring about device information to an address in an active configuration list through a communication unit (12), and determine to be abnormal when the result of the communication with respect to a common portion of a slave-side system (20) is different from the device information in the active configuration list.

TECHNICAL FIELD

The present invention relates to a control device.

BACKGROUND ART

In the field of factory automation (FA), various types of devices thatshare operation processes are controlled. In order to operate variouscontrollers, remote I/Os, and manufacturing equipment used foroperations in a certain area such as factory facilities in cooperation,an industrial network system called a field network that connects thisequipment is constructed.

In a general industrial network system, a master-slave network composedof various slave devices and master devices is used. A slave device is adevice that collects and controls data of facilities installed in afactory. The master device is a device called a programmable logiccontroller (PLC) that centrally manages these slave devices, forexample. DeviceNet (registered trademark) is also one type of such anindustrial network system.

In such a network system, an address (node address) is assigned to eachslave device. Communication frames formatted to have a predetermineddata structure are transmitted and received between a master device andslave devices using addresses, and communication is realized. The masterdevice has a configuration list including addresses assigned to eachslave device connected to the network system and device informationthereof in order to manage the slave devices. The configuration list isalso called a scan list.

FIG. 11 shows a specific example of such a configuration list. In theconfiguration list, each slave device connected to the network system islisted, and the address assigned to each slave device and its deviceinformation are tabulated. In FIG. 11, the number of input terminals andoutput terminals is stored as an example of device information. Forexample, the slave device includes an input terminal if it is an inputunit that receives a signal from a sensor. Further, for example, theslave device includes an output terminal if it is an output unit formotor control or the like.

The master device attempts to communicate with the address in theconfiguration list and inquires about the device information of theslave device. If the returned device information is different from thaton the configuration list, it is determined that there is aninconsistency in the configuration of the slave-side system. Inaddition, the same determination is made when communication with theslave device cannot be performed. Then, the input/output (IO)communication to each slave device, which is the communication forcontrolling the FA device, is stopped, and an abnormality is notifiedof. The FA administrator thereby detects an abnormality in the systemconfiguration and takes necessary measures.

In this way, in an industrial network such as DeviceNet (registeredtrademark), the master device checks the configuration of the slave-sidesystem with reference to the configuration list. The configuration listis a definitive list that is not rewritten while the network is running.This prevents occurrence of trouble resulting from inconsistencies inthe system configuration of the slave-side system. Further, even if aslave device having an address not listed in the configuration list isconnected to the network system, it is possible to efficiently controlthe slave-side system by not communicating with the device.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Patent Laid-Open No. 2014-146070

SUMMARY OF INVENTION Technical Problem

In a production process, it may be desired to change a portion of theprocess as the products to be produced are switched. Therefore, it maybe desirable to replace a portion of the configuration of the slave-sidesystem. However, as described above, in an industrial network using amaster device that checks the configuration of the slave-side systemusing the configuration list, the setup change in such a case iscomplicated.

In the setup change, after the control of the slave-side system by themaster device is stopped, the administrator needs to operate the masterdevice and rewrite the configuration list corresponding to thesubsequent production of products. However, rewriting takes time andthere is a risk of operation mistakes.

Alternatively, the administrator needs to load a created configurationlist from an external device called a tool or a configurator into themaster device and change the configuration list. By replacing theconfiguration list in this way, mistakes in rewriting can be prevented,but there is a risk of operation mistakes in the replacement itself. Inaddition, in the setup change, the administrator needs to prepare anexternal device first, and then operate the master device and theexternal device in cooperation with each other to rewrite theconfiguration list, which is complicated.

The present invention has been made in view of the above problems, andan object thereof is to realize a control device that can perform setupchange easily without requiring a complicated operation with respect toa partial change in the configuration of a slave-side system in a masterdevice (control device) that employs a configuration list.

Solution to Problem

The present invention adopts the following configuration in order tosolve the above-mentioned problems.

A control device according to one aspect of the present invention is acontrol device which is a master device used in a network system inwhich a plurality of slave devices constituting a slave-side system isconnected to the master device, the control device being able to controlthe slave-side system to switch between a first system configuration anda second system configuration in which a predetermined portion isdifferent from the first system configuration and other configurationsare common, the control device including: a communication unit thattransmits and receives data to and from the plurality of slave devices;a control unit that controls the communication unit; and a recordingunit having at least one configuration list which represents aconfiguration of the slave-side system and includes an address anddevice information of each of the slave devices, wherein, whencontrolling the first system configuration or the second systemconfiguration, the control unit performs communication for inquiringabout device information to an address in an active configuration listthrough the communication unit and determines that an abnormality hasoccurred at least when a result of the communication with respect to thecommon portion is different from the device information in the activeconfiguration list.

Advantageous Effects of Invention

According to the above configuration, it is possible to realize acontrol device that can perform setup change easily without requiring acomplicated operation with respect to setup change that incurs a partialchange in the configuration of a slave-side system in a master device(control device) that employs a configuration list.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing a network system to which a control deviceaccording to a first embodiment of the present invention is applied.

FIG. 2 is a configuration diagram showing the control device accordingto the first embodiment of the present invention.

FIG. 3 is a flowchart showing a procedure for setting a configurationlist in the control device according to the first embodiment of thepresent invention.

FIG. 4 is a flowchart showing the operation of the control deviceaccording to the first embodiment of the present invention.

FIG. 5 is a diagram showing a case of Example 1 of the present inventionin which (a) shows the state before the setup change, and (b) shows thestate after the setup change.

FIG. 6 is a diagram showing a case of Example 2 of the present inventionin which (a) shows the state before the setup change, and (b) shows thestate after the setup change.

FIG. 7 is a diagram showing a screen of a configurator for creating aconfiguration list applied to a control device according to a secondembodiment of the present invention.

FIG. 8 is a flowchart showing the operation of the control deviceaccording to the second embodiment of the present invention.

FIG. 9 is a diagram showing a case of Example 3 of the present inventionin which (a) shows the state before the setup change, and (b) shows thestate after the setup change.

FIG. 10 is a diagram showing a case of Example 4 of the presentinvention in which (a) shows the state before the setup change, and (b)shows the state after the setup change.

FIG. 11 is a diagram showing a configuration list in the prior art.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, an embodiment according to one aspect of the presentinvention (hereinafter, also referred to as “the present embodiment”)will be described with reference to the drawings.

§ 1 Application Example

First, an example of a situation in which the present invention isapplied will be described. A control device according to the presentembodiment is a master device used in a network system in which aplurality of slave devices constituting a slave-side system is connectedto the master device.

The control device according to the present embodiment, which is amaster device, can control the slave-side system to switch between afirst system configuration and a second system configuration in which apredetermined portion is different from the first system configurationand other configurations are common.

The control device according to the present embodiment includes acommunication unit, a control unit, and a recording unit. Thecommunication unit is a functional block that transmits and receivesdata to and from the plurality of slave devices. The control unit is afunctional block that controls the communication unit, executesprocessing of data acquired through the communication unit or from therecording unit, and outputs the data.

The recording unit is a functional block that stores, reads, and retainsdata. The recording unit has at least one configuration list includingthe address and device information of each slave device, whichrepresents the configuration of the slave-side system.

When controlling the first system configuration or the second systemconfiguration, the control unit performs communication for inquiringabout device information to an address in an active configuration listthrough the communication unit. As a result, when the result of thecommunication with respect to at least the common portion is differentfrom the device information in the active configuration list, it isdetermined that there is an abnormality.

According to the present embodiment, the control device, which is themaster device, applies the configuration list to check the configurationof the slave-side system. This prevents occurrence of trouble resultingfrom inconsistencies in the configuration of the slave-side system. Onthe other hand, a change in the predetermined partial configuration ofthe slave-side system is not determined to be abnormal. As a result, itis possible to realize a control device capable of performing setupchange easily without requiring a complicated operation with respect toa change in a predetermined partial configuration of the slave-sidesystem in a master device (control device) that employs a configurationlist.

§ 2 Configuration Example

(Overall Configuration Including Network System)

FIG. 1 is a schematic configuration diagram showing a network system 1including a control device 10 according to a first embodiment. Thenetwork system 1 includes a control device 10 which is a master deviceand a slave-side system 20 other than the control device 10. As aspecific example, DeviceNet (registered trademark) is used as thenetwork system 1.

A plurality of slave devices 21 is connected to the slave-side system20. A portion of the bundle of the slave-side system 20 is a partialsystem 201 (a predetermined portion). The network system 1, which is anFA system, is applied to the production of a certain product “a.” Then,product “a” produced by the partial system 201 is switched to anotherproduct “b” produced by another partial system 202 (a predeterminedportion). As described above, the network system 1 can produce differentproducts when a portion of the configuration of the slave-side system 20is changed.

The partial system 201 may be a so-called “Null” having no substance. Inthis case, replacing the partial system 201 with another partial system202 corresponds to additionally connecting the partial system 202 to theoriginal slave-side system 20. The partial system 202 may be a so-called“Null” having no substance. In this case, replacing the partial system201 with another partial system 202 corresponds to removing the partialsystem 201 from the original slave-side system 20. However, the partialsystem 201 and the partial system 202 are not both “Null” at the sametime. In this way, changing or replacing a portion of the configurationof the slave-side system is a concept including additional connection ofa partial system and removal of a partial system.

The control device 10, which is a master device, is connected to aconfigurator 90 via a higher-order network system 80 which is differentfrom the network system 1. As a specific example, Ethernet (registeredtrademark) is used as the higher-order network system 80. However, theconnection method between the control device 10 and the configurator 90is not limited to the one via the network system, and the devices may bedirectly connected to each other. In this case, as a specific example,serial communication such as Universal Serial Bus (USB) or RecommendedStandard 232 (RS232) may be applied to the connection.

The configurator 90 is a computer capable of collecting various piecesof data from the control device 10 by communicating with the controldevice 10. The configurator 90 is a computer capable of changing thesettings of the control device 10 and providing a control program and aconfiguration list to the control device 10. The configurator 90 mayinclude a display device 91 and an input device 92.

(Control Device Configuration)

FIG. 2 is a diagram showing an example of the configuration of thecontrol device 10 according to the first embodiment. The control device10 includes a control unit 11, a communication unit 12, a recording unit13, a list selection unit 14, a higher-order side interface 15, and anotification unit 16.

The communication unit 12 is a functional block that communicates withthe plurality of slave devices 21 of the slave-side system 20. Therecording unit 13 is a functional block that records, reads, and retainsdata.

The list selection unit 14 is a functional block for designating anactive configuration list from a plurality of configuration listsretained in the recording unit 13. The list selection unit 14 isprovided with a user interface such as a switch or a touch panel, onwhich an active configuration list is selected with an operationperformed by an administrator. The list selection unit 14 does notnecessarily have to be provided, and in that case, the control unit 11may select the configuration list in response to an instruction fromanother device through the communication unit 12 or the higher-orderside interface 15. Alternatively, the selection of the list may beinstructed by a control program for controlling the slave device 21,executed by the control device 10.

The higher-order side interface 15 is a functional block thatcommunicates with the configurator 90 and the like through thehigher-order network system 80.

The notification unit 16 is a functional block that notifies anadministrator, an operator, or the like of an abnormality in theconfiguration of the network system 1. As means for notification, visualmeans, auditory means and other means may be used. The notification unit16 may include a display device and notify of an abnormality withcharacters, illustrations, or the like. Alternatively, the notificationunit 16 may include a lamp or a buzzer and notify by lighting or ringingthereof.

The notification unit 16 does not necessarily have to be provided, andin that case, the control unit 11 may notify other devices of anabnormality through the communication unit 12 or the higher-order sideinterface 15.

The control unit 11 controls these functional blocks including thecommunication unit 12. The control unit 11 may execute processing of thedata acquired through the communication unit 12, the list selection unit14, the higher-order side interface 15, or from the recording unit 13,and adjust the control according to the processing result. The controlunit 11 may execute processing of the data acquired through thecommunication unit 12, the list selection unit 14, the higher-order sideinterface 15, or from the recording unit 13, and output the processingresult to another functional block.

The recording unit 13 has a plurality of configuration listsrepresenting the configuration of the slave-side system 20. Eachconfiguration list is a table including the address and deviceinformation of a slave device 21, as in FIG. 11.

(Configuration List)

In the first embodiment, the recording unit 13 has a configuration listL1 (first configuration list) showing the slave-side system 20 (firstsystem configuration) including the partial system 201. The recordingunit 13 also has a configuration list L2 (second configuration list)showing the slave-side system 20 (second system configuration) in astate where the partial system 201 is replaced with the partial system202. The slave-side system 20 (first system configuration) shown in theconfiguration list L1 and the slave-side system 20 (second systemconfiguration) shown in the configuration list L2 are different in apredetermined portion (the partial system 201 and the partial system202) of the slave-side system 20, and other portions (common portions)are the same.

As an example of device information in each configuration list, thenumbers of input terminals and output terminals corresponding to digitalsignals are stored. For example, the slave device 21 includes an inputterminal if it is an input unit that receives a signal from a sensor.Further, for example, the slave device 21 includes an output terminalfor outputting a control signal if it is an output unit for motorcontrol or the like. The number of input terminals corresponds to thenumber of bits of the digital signal received by the input unit, and thenumber of output terminals corresponds to the number of bits of thecontrol digital signal output by the output unit.

When the slave device 21 is an input unit that receives an analogsignal, the number of input terminals corresponds to the number of bitsof the digital signal obtained by A/D converting the received analogsignal. When the slave device 21 is an output unit that outputs ananalog signal, the number of output terminals corresponds to the numberof bits of the digital signal for D/A converting and outputting theanalog signal.

FIG. 3 is a flowchart for explaining the operation when a plurality ofconfiguration lists is retained in the recording unit 13. The operationin which the administrator of the network system 1 causes the controldevice 10 to retain a plurality of configuration lists using theconfigurator 90 will be described below as an example. The configurator90 supports the administrator by communicating with the control device10 and executing the application for realizing the operations of thefollowing steps S11 to S15 on the control device 10.

(Step S11)

The administrator deletes the configuration list stored in the recordingunit 13 as needed through the configurator 90.

(Step S12)

Subsequently, the administrator selects the configuration list L1 storedas data in the configurator 90, loads it into the control device 10, andstores it in the recording unit 13.

(Step S13)

Subsequently, the administrator selects the configuration list L2 storedas data in the configurator 90, loads it into the control device 10, andstores it in the recording unit 13.

(Step S14)

Subsequently, the administrator selects an active configuration listfrom the configuration list stored in the recording unit 13 through theconfigurator 90.

(Step S15)

Subsequently, the administrator makes the selected configuration list L1active in the control device 10 through the configurator 90. The controldevice 10 activates the configuration list L1 in the recording unit 13.

Through the above series of operations, the configuration list L1 andthe configuration list L2 are stored in the recording unit 13, and oneof them (the configuration list L1) is put into an active state. In theabove description, the operation using the configurator 90 has beenexemplified, but the application of the present invention is not limitedto this method. The administrator may directly operate and set thecontrol device 10. In this case, the configuration list may be loadedfrom an appropriate recording device such as a memory card to thecontrol device 10.

(Operation of Control Device)

When the active configuration list is set as described above, thecontrol device 10 can operate the network system 1. While the networksystem 1 is in operation, the control device 10 performs IOcommunication related to the control of each slave device 21 withreference to an active configuration list in order to control theslave-side system 20. The control device 10 executes the followingcharacteristic operation for checking the configuration of theslave-side system 20 in parallel with the IO communication.

FIG. 4 is a flowchart illustrating a characteristic operation forchecking the configuration of the slave-side system 20, which isexecuted by the control device 10 according to the first embodiment. Thecontrol device 10 repeatedly executes the following flow from step S21to step S26 while the network system 1 is in operation.

(Step S21)

The control unit 11 refers to the active configuration list L1 andperforms communication for inquiring about device information to theaddress assigned to the slave device 21 in the configuration list. Then,it is determined whether the device information from the slave device 21matches the configuration list L1. If it is determined that they match(YES in S21), the process proceeds to step S23, and in other cases (NOin S21), the process proceeds to step S22.

(Step S22)

The control unit 11 controls the communication unit 12 to stop IOcommunication with the slave device 21 described in the configurationlist. That is, the control device 10 stops the control of the slave-sidesystem 20. The control unit 11 controls the notification unit 16 tonotify of an abnormality. Step S22 continues unless the administratorresolves the abnormal condition. Then the flow ends.

(Step S23)

The control unit 11 determines whether the configuration list has beenreselected (selection of the configuration list L2) through the listselection unit 14. If it is determined that the reselection has beenmade (YES in S23), the process proceeds to step S24, and in other cases(NO in S23), the flow ends.

(Step S24)

The control unit 11 controls the communication unit 12 to stop IOcommunication with the slave device 21 described in the configurationlist. That is, the control device 10 stops the control of the slave-sidesystem 20.

(Step S25)

Subsequently, the control unit 11 activates the selected configurationlist L2 in the recording unit 13.

(Step S26)

Subsequently, the control unit 11 controls the communication unit 12 toresume IO communication with the slave device 21 described in theconfiguration list. That is, the control device 10 resumes control ofthe slave-side system 20. Then the flow ends.

§ 3 Operation Example

An embodiment as an operation example of the control device 10 accordingto the first embodiment is shown below.

Example 1

FIG. 5 is a diagram for explaining the operation of the control device10 of Example 1. Example 1 is a case in which the slave device D isadded to the slave-side system 20 composed of the slave devices A to Caccording to the switching of the product to be produced. (a) and 5(b)of FIG. 5 show the configuration of the network system 1 when producingproduct “a” before switching and product “b” after switching,respectively.

The configuration list L1 corresponding to the slave-side system 20before switching is a table for slave devices A to C, and addresses #1to #3 are assigned to the slave devices A to C, respectively. Theconfiguration list L2 corresponding to the slave-side system 20 afterswitching is a table for slave devices A to D, and the slave device D towhich the address #4 is assigned is added from the configuration listL1. The configuration list L1 and the configuration list L2 are retainedin the recording unit 13 of the control device 10.

In the state of producing the product “a” before switching shown in (a)of FIG. 5, the configuration of the slave-side system 20 matches theconfiguration list L1. While the network system 1 is in operation, thecontrol device 10 executes a control program for producing the product“a”, and also performs communication for inquiring about deviceinformation to the addresses (#1 to #3) in the configuration list L1.The device information obtained from each of the slave devices A to Cmatches the device information in the configuration list L1 (YES in stepS21). Therefore, the IO communication is not stopped and the abnormalityis not notified due to the inconsistency in the configuration of theslave-side system 20.

Next, the operation performed by the administrator of the network system1 at the time of setup change will be described. When the requiredproduction of the product “a” is completed, the administrator operatesthe control device 10 to end the control program for producing theproduct “a”. Then, the IO communication between the control device 10and the slave devices A to C is stopped.

The administrator connects the slave device D to the slave-side system20 (in the example of FIG. 1, it corresponds to replacing the partialsystem 201 with the partial system 202 and reconnecting). Next, theadministrator operates the control device 10 to select the configurationlist L2 (YES in step S23). Then, the active configuration list isswitched to the configuration list L2 (step S25).

The administrator operates the control device 10 to start the executionof the control program for producing the product “b”. In this way, thesetup change is completed.

Then, IO communication is started between the control device 10 and theslave devices A to D, and the product “b” after switching shown in (b)of FIG. 5 is produced. The device information obtained from each of theslave devices A to D matches the device information in the configurationlist L2 (YES in step S21). Therefore, the IO communication is notstopped and the abnormality is not notified due to the inconsistency inthe configuration of the slave-side system 20.

Example 2

FIG. 6 is a diagram for explaining the operation of the control device10 of Example 2. Example 2 is a case in which the slave device C isreplaced with the slave device E as the product to be produced isswitched, and the other configurations are the same as those of Example1.

In Example 2, the configuration list L2 corresponding to the slave-sidesystem 20 after switching is a table for the slave devices A, B, and E.The configuration list L2 is modified from the configuration list L1 sothat the slave device E is assigned to the address #3. The configurationlist L1 and the configuration list L2 are retained in the recording unit13 of the control device 10.

In the state of producing the product “a” before switching shown in (a)of FIG. 6, the configuration of the slave-side system 20 matches theconfiguration list L1. While the network system 1 is in operation, thecontrol device 10 executes a control program for producing the product“a”, and also performs communication for inquiring about deviceinformation to addresses #1 to #3 in the configuration list L1. Thedevice information obtained from each of the slave devices A to Cmatches the device information in the configuration list L1 (YES in stepS21). Therefore, the IO communication is not stopped and the abnormalityis not notified due to the inconsistency in the configuration of theslave-side system 20.

The setup change operation for switching the products to be produced isthe same as that in Example 1. When the execution of the control programfor producing the product “b” is started, IO communication is startedbetween the control device 10 and the slave devices A, B, and E, and theproduct “b” after switching shown in (b) of FIG. 6 is produced. Thedevice information obtained from each of the slave devices A, B, and Ematches the device information in the configuration list L2 (YES in stepS21). Therefore, the IO communication is not stopped and the abnormalityis not notified due to the inconsistency in the configuration of theslave-side system 20.

§ 4 Operation and Effect

According to the first embodiment, since the control device 10 checksthe configuration of the slave-side system 20 using the configurationlist, it is possible to quickly detect an abnormality in theconfiguration. Each configuration list has a property that it isdetermined when the configuration of the slave-side system 20 requiredfor the production of the product “a” and the product “b” is determined,for example. It is not necessary to rewrite the configuration list everysetup change, and it is possible to prevent occurrence of a malfunctiondue to a mistake in rewriting.

Since only the slave device having the address described in theconfiguration list is accessed, the communication cycle can be shortenedeven if the slave device not listed in the configuration list isconnected to the slave-side system 20.

The control device 10 has a plurality of configuration lists in which apredetermined portion of the slave-side system 20 has a differentconfiguration, and can easily switch the active configuration list amongthem. Therefore, the administrator of the network system 1 can easilycomplete the setup change operation for switching the products to beproduced. At the time of setup change, the administrator does not needto perform a complicated operation in the prior art as described in theproblem to be solved by the invention. Since it is not necessary to useother devices such as tools and configurators other than the controldevice 10 at the same time when changing the configuration list, and thetime required for transferring or rewriting data from other devices isnot required, it is possible to quickly switch the configuration list atthe production site.

Therefore, according to the control device 10 according to the firstembodiment, the setup change can be efficiently executed, and theoccurrence of mistakes due to complicated operation is suppressed. As aresult, an efficient production line can be realized.

As a specific example in the first embodiment, when DeviceNet(registered trademark) is applied, various network topologies such asT-branch and star type can be adopted as the topology of the networksystem 1. Therefore, it is highly compatible with the present inventionin which a portion of the configuration of the slave-side system 20 ischanged according to the product to be produced.

In the above, in the first embodiment including Example 1 and Example 2,the case where there are two configuration lists has been described indetail as an example. However, the number of configuration lists is notlimited to this, and may be three or more.

Second Embodiment

Another embodiment of the present invention is described below. Forconvenience of explanation, the same reference numerals are added to thecomponents having the same functions as the components described in theabove embodiment, and the description will not be repeated.

The configuration of the control device 10 according to the secondembodiment is the same as that of the first embodiment shown in FIG. 2.The configuration of the network system 1 to which the control device 10according to the second embodiment is applied is the same as that of thefirst embodiment shown in FIG. 1. However, in the second embodiment, thenumber of configuration lists L retained in the recording unit 13 may beat least one, which is different from the first embodiment. Further, inthe second embodiment, the content of the configuration list L isdifferent from that of the first embodiment.

(Configuration List)

In the control device 10 according to the second embodiment, theconfiguration list L (third configuration list) includes the addressassigned to each slave device and switching information (additionalinformation) of each slave device as well as the device informationthereof. Here, the switching information is information indicating thatthe configuration of a predetermined portion of the slave-side system 20is changed due to the switching of the product to be produced. Thecontent of the switching information (additional information) is theinformation “with switching” (second information) indicating that thereis switching, or the information “without switching” (first information)indicating that there is no switching.

The switching information of the slave device 21 belonging to thepartial system 201, which is shown in FIG. 1 and is used for theproduction of the product “a” and not used for the production of theproduct “b”, is set to “with switching”. The switching information ofthe slave device 21 belonging to the partial system 202, which is notused in the production of the product “a” but is used in the productionof the product “a”, is set to “with switching”. In the slave-side system20 shown in FIG. 1, the switching information of the slave devices 21 ofthe common portion that does not belong to the partial system 201 andthe partial system 202 is set to “without switching”.

Note that “without switching” and “with switching” in the switchinginformation (additional information) are merely names indicating twodifferent states of the switching information, and the terms themselveshave no meaning. Such names are merely used in the specification forconvenience in order to make the operation easier to understand. It isno difference in describing “without switching” and “with switching” as“first information” and “second information”, or as symbols “X” and “Y”,respectively. In the configuration list L as digital informationretained in the recording unit 13, as an example, it can be stored as aflag such that “without switching” and “with switching” are “1” and “0”,respectively.

FIG. 7 shows an example of the screen of the display device 91 when theadministrator of the network system 1 uses the configurator 90 to setthe switching information in the configuration list. On the screen, theslave devices 21 listed in the configuration list are displayed in alist with illustrations, and a check box for setting switchinginformation is arranged for each slave device. In FIG. 7, it is shownthat the slave devices 21 at addresses #9 and #10 are checked, and thatthese slave devices 21 are set to “with switching”. The slave devices 21at other addresses are not selected (checked) by the administrator andare set to “without switching”.

The configurator 90 communicates with the control device 10 to set andactivate the configuration list in the control device 10. Theconfigurator 90 supports the administrator by executing an applicationthat realizes these operations.

(Operation of Control Device)

While the network system 1 is in operation, the control device 10performs IO communication related to the control of each slave device 21with reference to an active configuration list in order to control theslave-side system 20. The control device 10 executes the followingcharacteristic operation for checking the configuration of theslave-side system 20 in parallel with the IO communication.

FIG. 8 is a flowchart illustrating a characteristic operation forchecking the configuration of the slave-side system 20, which isexecuted by the control device 10 according to the second embodiment.The control device 10 repeatedly executes the following flow from stepS31 to step S40 while the network system 1 is in operation.

(Step S31)

Step S31 is a start point of the loop with step S40 as the return point.The initial value of the address number N is set to 0, N is increased(incremented) by 1 each time the process proceeds from step S31 to stepS32, and the steps of S32 and later are executed as long as the maximumvalue of the address in the configuration list is not exceeded, and theloop is repeated.

(Step S32)

The control unit 11 attempts to communicate with the slave device 21having the address number N in the configuration list L through thecommunication unit 12, and acquires device information from the slavedevice 21.

(Step S33)

Subsequently, the control unit 11 determines whether the deviceinformation matches the device information in the configuration list L.Even if communication with the slave device 21 having the address numberN cannot be performed, it is considered that the device information doesnot match the device information in the configuration list L. If it isdetermined that it matches the device information in the configurationlist L (YES in S33), the process proceeds to step S35, and in othercases (NO in S33), the process proceeds to step S34.

(Step S34)

The control unit 11 determines whether the switching information of theslave device 21 having the address number N in the configuration list Lis “with switching”. If it is determined that it is “with switching”,the process proceeds to step S36 (YES in S34), and in other cases (NO inS34), the process proceeds to step S37.

(Step S35)

The control unit 11 performs IO communication with the slave device 21having the address number N. In this case, the abnormality is notnotified. This is because the actual situation matches the deviceinformation in the configuration list L. Next, the process proceeds tostep S40.

(Step S36)

The control unit 11 does not perform IO communication with the slavedevice 21 having the address number N. In this case, the abnormality isnot notified. This is to prevent notification of an abnormality even ifthe slave device 21 is not connected when the switching information is“with switching”. Next, the process proceeds to step S40.

(Step S37)

The control unit 11 does not perform IO communication with the slavedevice 21 having the address number N.

(Step S38)

Subsequently, the control unit 11 controls the notification unit 16 tonotify that the slave device 21 having the address number N is abnormal.This is to ask the administrator to take measures.

(Step S39)

Subsequently, the control unit 11 determines whether the abnormality hasbeen released by the administrator. If it is determined that theabnormality has been released (YES in S39), the process proceeds to stepS41, and in other cases (NO in S39), the process proceeds to step S38.

(Step S40)

Step S40 is the return point of the loop. When the loop is exited by thedetermination in step S31, the flow ends.

As described above, the control device 10 performs IO communication withthe slave device 21 of each address number if it matches theconfiguration list L (step S35), and does not perform IO communicationif it does not match (step S36, step S37). Here, even when communicationwith the slave device 21 is not possible, it is considered that thedevice information does not match the device information in theconfiguration list L.

The control device 10 notifies the slave device 21 of each addressnumber of an abnormality when it does not match the configuration list Land the switching information is “without switching” (step S38). Even ifit does not match the configuration list L, when the switchinginformation is “with switching”, no abnormality is notified.

In the control of IO communication, the control device 10 executes IOcommunication with the slave device 21 having an address numberdetermined to perform IO communication, and does not execute IOcommunication (does not control slave devices) with the slave device 21having an address number determined not to perform IO communication.

Example 3

With reference to FIG. 9, Example 3 as an operation example of thecontrol device 10 according to the second embodiment is shown. FIG. 9 isa diagram for explaining the operation of the control device 10 ofExample 3. Example 3 is a case in which the slave device D is added tothe slave-side system 20 composed of the slave devices A to C accordingto the switching of the products to be produced. (a) and (b) of FIG. 9show the configuration of the network system 1 when producing theproduct “a” before switching and the product “b” after switching,respectively.

The configuration list L is a table for the slave devices A to D, andaddresses #1 to #4 are assigned to the slave devices A to D,respectively. The switching information of the slave devices A to C inwhich a device is not replaced before and after the setup change is setto “without switching”. The switching information of the slave device Din which a device is replaced before and after the setup change is setto “with switching”.

In the state of producing the product “a” before switching shown in (a)of FIG. 9, the configuration of the slave-side system 20 matches theconfiguration list L for the addresses #1 to #3 (slave devices A to C)(YES in step S33). Therefore, it is controlled so that IO communicationwith these devices is performed (step S35). In addition, there is nonotification of abnormality regarding these devices.

Since the slave device D is not connected to the network system 1,communication is not established for the address #4 (NO in step S33).Since the switching information is “with switching” in the configurationlist L (YES in step S34), it is controlled so that IO communication isnot performed (step S36). In addition, there is no notification ofabnormality regarding the address #4.

Next, the operation performed by the administrator of the network system1 at the time of setup change will be described. When the requiredproduction of the product “a” is completed, the administrator operatesthe control device 10 to end the control program for producing theproduct “a”. Then, the IO communication between the control device 10and the slave devices A to C is stopped.

The administrator connects the slave device D to the slave-side system20 (in the example of FIG. 1, it corresponds to replacing the partialsystem 201 with the partial system 202 and reconnecting). Next, theadministrator operates the control device 10 to execute the controlprogram for producing the product “b”. In this way, the setup change iscompleted.

In the state of producing the product “b” after switching shown in (b)of FIG. 9, the configuration of the slave-side system 20 matches theconfiguration list L for addresses #1 to #4 (slave devices A to D) (YESin step S33). Therefore, it is controlled so that IO communication tothese devices is performed (step S35). In addition, there is nonotification of abnormality regarding these devices.

Example 4

With reference to FIG. 10, Example 4 as another operation example of thecontrol device 10 according to the second embodiment is shown. FIG. 10is a diagram for explaining the operation of the control device 10 ofExample 4. Example 4 is a case in which the slave device C is replacedwith the slave device E due to switching of the product, and the otherconfigurations are the same as those of Example 3.

The configuration list L is a table for slave devices A to C and E, andaddresses #1 to #4 that do not overlap are assigned to slave devices Ato C and E, respectively. The switching information of the slave devicesA and B in which a device is not replaced before and after the setupchange is set to “without switching”. The switching information of theslave devices C and E in which a device is replaced is set to “withswitching”.

In the state of producing the product “a” before switching shown in (a)of FIG. 10, the configuration of the slave-side system 20 matches theconfiguration list L for the addresses #1 to #3 (slave devices A to C)(YES in step S33). Therefore, it is controlled so that IO communicationto these devices is performed (step S36). In addition, there is nonotification of abnormality regarding these devices.

Since the slave device E is not connected to the network system 1,communication is not established for the address #4 (NO in step S33).However, since the switching information is “with switching” in theconfiguration list L (YES in step S34), it is controlled so that 10communication is not performed (step S36). In addition, there is nonotification of abnormality regarding address #4.

Next, the operation performed by the administrator of the network system1 at the time of setup change will be described. When the requiredproduction of the product “a” is completed, the administrator operatesthe control device 10 to end the control program for producing theproduct “a”. Then, the IO communication between the control device 10and the slave devices A to C is stopped.

The administrator replaces the slave device C with the slave device E(in the example of FIG. 1, it corresponds to replacing the partialsystem 201 with the partial system 202 and reconnecting). Next, theadministrator operates the control device 10 to execute the controlprogram for producing the product “b”. In this way, the setup change iscompleted.

In the state of producing the product “b” after switching shown in (b)of FIG. 10, the configuration of the slave-side system 20 matches aconfiguration list L for addresses #1, #2, and #4 (slave devices A, B,E) (YES in step S33). Therefore, it is controlled so that IOcommunication to these devices is performed (step S35). In addition,there is no notification of abnormality regarding these devices.

Since the slave device C is not connected to the network system 1,communication is not established for the address #3 (NO in step S33).However, since the switching information is “with switching” in theconfiguration list L (YES in step S34), it is controlled so that 10communication is not performed (step S37). In addition, there is nonotification of abnormality regarding address #3.

(Operation and Effect)

According to the second embodiment, since the control device 10 checksthe configuration of the slave-side system 20 using the configurationlist, it is possible to quickly detect an abnormality in theconfiguration. At that time, the abnormality is not notified to theaddress whose switching information is set to “with switching”.Therefore, the administrator of the network system 1 can execute setupchange without notification of an abnormality or stopping the networksystem 1 even if the configuration list is not switched by setting theswitching information to “with switching” for devices of which theconnection state is different before and after the setup change.Therefore, the administrator of the network system 1 can quickly andextremely easily complete the setup change operation for switching theproduct to be produced, which is very convenient for the administrator.

The configuration list L has a property that it is determined when theconfiguration of the slave-side system 20 required for the production ofthe product “a” and the product “b” is determined, for example. It isnot necessary to rewrite the configuration list L every setup change,and it is possible to prevent occurrence of a malfunction due to amistake in rewriting.

Since the control device 10 accesses only the slave device of theaddress described in the configuration list and actually connected, thecommunication cycle (control cycle) can be shortened.

Therefore, according to the control device 10 according to the secondembodiment, the setup change can be efficiently executed, and theoccurrence of mistakes due to a complicated operation is alsosuppressed. As a result, an efficient production line can be realized.

As a specific example in the second embodiment, when DeviceNet(registered trademark) is applied, various network topologies such asT-branch and star type can be adopted as the topology of the networksystem 1. Therefore, it is highly compatible with the present inventionin which a portion of the configuration of the slave-side system 20 ischanged according to the product to be produced.

Example of Realization by Software

The functional block (particularly, the control unit 11) of the controldevice 10 may be realized by a logic circuit (hardware) formed in anintegrated circuit (IC chip) or the like, or may be realized bysoftware.

In the latter case, the control device 10 includes a computer thatexecutes commands of a program that is software that realizes eachfunction. The computer includes, for example, one or more processors andincludes a computer-readable recording medium that stores the program.

Then, in the computer, the processor reads the program from therecording medium and executes the program, whereby the object of thepresent invention is achieved.

As the processor, for example, a Central Processing Unit (CPU) can beused. As the recording medium, in addition to a “non-temporary tangiblemedium” such as a Read Only

Memory (ROM), a tape, a disk, a card, a semiconductor memory, aprogrammable logic circuit, or the like can be used.

A Random Access Memory (RAM) for expanding the above program may befurther provided.

The program may be supplied to the computer via an arbitrarytransmission medium (communication network, broadcast wave, and thelike) capable of transmitting the program.

It should be noted that one aspect of the present invention can also berealized in the form of a data signal embedded in a carrier wave, inwhich the above program is embodied by electronic transmission.

SUMMARY

A control device according to one aspect of the present invention is acontrol device which is a master device used in a network system inwhich a plurality of slave devices constituting a slave-side system isconnected to the master device, the control device being able to controlthe slave-side system to switch between a first system configuration anda second system configuration in which a predetermined portion isdifferent from the first system configuration and other configurationsare common, the control device including: a communication unit thattransmits and receives data to and from the plurality of slave devices;a control unit that controls the communication unit; and a recordingunit having at least one configuration list which represents aconfiguration of the slave-side system and includes an address anddevice information of each of the slave devices, wherein whencontrolling the first system configuration or the second systemconfiguration, the control unit performs communication for inquiringabout device information to an address in an active configuration listthrough the communication unit and determines that an abnormality hasoccurred at least when a result of the communication with respect to thecommon portion is different from the device information in the activeconfiguration list.

According to the above configuration, it is possible to realize acontrol device that can perform setup change easily without requiring acomplicated operation with respect to setup change which incurs apartial change in the configuration of a slave-side system in a masterdevice (control device) that employs a configuration list.

The control device according to the aspect may further include a listselection unit, the recording unit may have a first configuration listrepresenting the first system configuration and a second configurationlist representing the second system configuration, the activeconfiguration list may be the first configuration list or the secondconfiguration list designated by the list selection unit, and thecontrol unit may determine that an abnormality has occurred when theresult of the communication is different from the device information inthe active configuration list.

According to the above configuration, a specific configuration isrealized in which it is determined that an abnormality has not occurredwith respect to a predetermined partial change in the configuration of aslave-side system in a master device (control device) that employs aconfiguration list.

In the control device according to the aspect, the control unit maycontrol the communication unit to stop transmission and reception ofdata to and from the slave-side system when the control unit determinesthat the abnormality has occurred.

According to the above configuration, when the configuration of theslave-side system is incorrect, the network system can be stopped andthe network system (production process) can be prevented from performingan incorrect operation.

In the control device according to the aspect, the recording unit mayhave, as the configuration list, a third configuration list that isactive when controlling the first system configuration and the secondsystem configuration, the third configuration list may further includeadditional information about each of the slave devices, the additionalinformation may be set in first information for the common portion andin second information for the others, and when the result of thecommunication with a slave device in the third configuration list isdifferent from the device information in the third configuration list,the control unit may determine that the abnormality has occurred if theadditional information of the slave device is the first information.

According to the above configuration, a specific configuration isrealized in which it is determined that an abnormality has not occurredwith respect to a predetermined partial change in the configuration of aslave-side system in a master device (control device) that employs aconfiguration list. In addition, it is possible to construct aproduction system with particularly high setup change efficiency.

In the control device according to the aspect, when the result of thecommunication with the slave device in the third configuration list isdifferent from the device information in the third configuration list,the control unit may control the communication unit to stop transmissionand reception of data to and from the slave device.

According to the above configuration, when the configuration of theslave-side system is incorrect, it is possible to stop the transmissionand reception of data with the incorrect specific slave device, and itis possible to prevent the incorrect operation from being executed.

The control device according to the aspect may further include anotification unit, and the control unit may notify of the abnormalitythrough the notification unit the result of the determination isabnormal.

According to the above configuration, the administrator of the networksystem can immediately recognize the occurrence of the abnormality.

The present invention is not limited to the above-described embodimentsand examples, various modifications can be made within the scope of theclaims, and the embodiments obtained from appropriate combinations ofthe technical means disclosed in different embodiments and examples arealso included in the technical scope of the present invention.

REFERENCE SIGNS LIST

-   -   1 Network system    -   10 Control device    -   11 Control unit    -   12 Communication unit    -   13 Recording unit    -   14 List selection unit    -   15 Higher-order side interface    -   16 Notification unit    -   20 Slave-side system    -   201, 202 Partial system (predetermined portion of slave-side        system)    -   21 Slave device    -   80 Higher-order network system    -   90 Configurator    -   91 Display device    -   92 Input device    -   L1 Configuration list (first configuration list)    -   L2 Configuration list (second configuration list)    -   L Configuration list (third configuration list)

1. A control device which is a master device used in a network system inwhich a plurality of slave devices constituting a slave-side system isconnected to the master device, the control device being able to controlthe slave-side system to switch between a first system configuration anda second system configuration in which a predetermined portion isdifferent from the first system configuration and other configurationsare common, the control device comprising: a communication unit thattransmits and receives data to and from the plurality of slave devices;a control unit that controls the communication unit; and a recordingunit having at least one configuration list which represents aconfiguration of the slave-side system and includes an address anddevice information of each of the slave devices, wherein, whencontrolling the first system configuration or the second systemconfiguration, the control unit performs communication for inquiringabout device information to an address in an active configuration listthrough the communication unit and determines that an abnormality hasoccurred at least when a result of the communication with respect to acommon portion is different from the device information in the activeconfiguration list.
 2. The control device according to claim 1, furthercomprising a list selection unit, wherein the recording unit has a firstconfiguration list representing the first system configuration and asecond configuration list representing the second system configuration,the active configuration list is the first configuration list or thesecond configuration list designated by the list selection unit, and thecontrol unit determines that the abnormality has occurred when theresult of the communication is different from the device information inthe active configuration list.
 3. The control device according to claim2, wherein the control unit controls the communication unit to stoptransmission and reception of data to and from the slave-side systemwhen the control unit determines that the abnormality has occurred. 4.The control device according to claim 1, wherein the recording unit has,as the configuration list, a third configuration list that is activewhen controlling the first system configuration and the second systemconfiguration, the third configuration list further includes additionalinformation about each of the slave devices, the additional informationis set in first information for the common portion and in secondinformation for other portions, and when the result of the communicationwith a slave device in the third configuration list is different fromthe device information in the third configuration list, the control unitdetermines that the abnormality has occurred if the additionalinformation of the slave device is the first information.
 5. The controldevice according to claim 4, wherein, when the result of thecommunication with the slave device in the third configuration list isdifferent from the device information in the third configuration list,the control unit controls the communication unit to stop transmissionand reception of data to and from the slave device.
 6. The controldevice according to claim 1, further comprising a notification unit,wherein the control unit notifies of the abnormality through thenotification unit when a result of determination is abnormal.
 7. Thecontrol device according to claim 2, further comprising a notificationunit, wherein the control unit notifies of the abnormality through thenotification unit when a result of determination is abnormal.
 8. Thecontrol device according to claim 3, further comprising a notificationunit, wherein the control unit notifies of the abnormality through thenotification unit when a result of determination is abnormal.
 9. Thecontrol device according to claim 4, further comprising a notificationunit, wherein the control unit notifies of the abnormality through thenotification unit when a result of determination is abnormal.
 10. Thecontrol device according to claim 5, further comprising a notificationunit, wherein the control unit notifies of the abnormality through thenotification unit when a result of determination is abnormal.